Conventionally, bus bars have been used for electrical connection. For bus bars used in motors or other devices to which high-voltage high-amperage currents are applied, plate-shaped bus bars having a great surface area are used in terms of heat radiation and suppression of high-frequency electrical resistance (refer to, for example, Patent Document 1). The plate-shaped bus bars are produced by punching or bending a metal plate such as a copper plate or an aluminum plate. Further, terminals on both ends of the bus bars are connected by screwing.